The nucleomorphin gene numA1 from Dictyostelium codes for a multi-domain, calmodulin binding protein that regulates nuclear number. To gain insight into the regulation of numA, we assessed the effects of the stalk cell differentiation inducing factor-1 (DIF-1), an extracellular signalling molecule, on the expression of numA1 RNA and protein. For comparison, the extracellular signalling molecules cAMP (mediates chemotaxis, prestalk and prespore differentiation) and ammonia (NH(3)/NH(4)(+); antagonizes DIF) were also studied. Starvation, which is a signal for multicellular development, results in a greater than 80% decrease in numA1 mRNA expression within 4 h. Treatment with ammonium chloride led to a greater than 90% inhibition of numA1 RNA expression within 2 h. In contrast, the addition of DIF-1 completely blocked the decrease in numA1 gene expression caused by starvation. Treatment of vegetative cells with cAMP led to decreases in numA1 RNA expression that were equivalent to those seen with starvation. Western blotting after various morphogen treatments showed that the maintenance of vegetative levels of numA1 RNA by DIF-1 in starved cells was reflected in significantly increased numA1 protein levels. Treatment with cAMP and/or ammonia led to decreased protein expression and each of these morphogens suppressed the stimulatory effects of DIF-1. Protein expression levels of CBP4a, a calcium-dependent binding partner of numA1, were regulated in the same manner as numA1 suggesting this potential co-regulation may be related to their functional relationship. NumA1 is the first calmodulin binding protein shown to be regulated by developmental morphogens in Dictyostelium being upregulated by DIF-1 and down-regulated by cAMP and ammonia.

BACKGROUND

Pemphigus vulgaris is characterized by relapses and remission, and there are currently no sensitive markers to predict remission.

OBJECTIVE

Our purpose was to determine if direct immunofluorescence (DIF) performed during clinical remission of pemphigus is useful in management of the disease.

METHODS

Twenty-eight patients with pemphigus that was in clinical remission (i.e., patients who were taking low-dose prednisolone [10 mg/day] and had been blister-free for at least 6 months) underwent DIF. Therapy was then discontinued and patients were prospectively followed up for 5 years.

RESULTS

Twenty-two patients had negative results and six patients had positive results of DIF. The disease remained in remission in three quarters of the patients with negative results of DIF. Of those who had a relapse, intercellular C3 on DIF and oral lesions on initial presentation were important risk factors, and the relapses in patients with negative results of DIF were mild. The biopsy site was unimportant. All patients with positive results of DIF had major relapses within 3 months of cessation of therapy.

CONCLUSIONS

DIF should be performed before therapy is discontinued. A negative DIF finding is a good indicator of remission in pemphigus.

A fibroblast-derived differentiation inducing factor (F-DIF) purified from medium conditioned by a human fibroblast cell line (WI-26VA4) induced differentiation of human monocytic leukemia cell lines (U-937, THP-1) into cells with macrophage characteristics. F-DIF alone induced the differentiation of ML-1 cells only marginally, but it synergistically increased the differentiation when combined with TNF. Interferon-gamma, tumor necrosis factor, GM-CSF, interleukin-1 and interlukin-4 synergistically enhanced the differentiation of U-937 cells when combined with F-DIF.

A cutaneous eruption simulating insect bites has been repeatedly described in association with chronic lymphocytic leukemia (CLL). It was only rarely described with mantle cell lymphoma (MCL). Our study was performed to elucidate the clinical, histologic, immunopathological, and molecular characteristics of insect bite like reaction (IBLR) associated with MCL. The clinical presentation and histologic findings in 3 IBLR cases associated with MCL were found to be similar to 3 IBLR cases associated with CLL. The eruptions consisted of itchy erythematous papules, nodules, plaques, and vesicles. Non-vesicular lesions were characterized histologically by normal or mildly spongiotic epidermis. Vesicular lesions were characterized by marked spongiosis and intraepidermal spongiotic vesicles containing eosinophils, or marked subepidermal edema occasionally leading to a dermoepidermal separation. Most of the lesions were characterized by superficial and mid dermal to deep perivascular and interstitial, and occasionally periadnexal, inflammatory-cell infiltrate consisting of mononuclear cells and eosinophils. The densities of the infiltrates varied and the inflammatory-cell infiltrate extended often into the fat lobules. Neutrophils and nuclear dust were found more frequently and abundantly in the IBLR lesions associated with MCL. Immunophenotyping, direct immunofluorescence (DIF) tests, and IgH gene rearrangement studies were performed in the lesions associated with MCL only. The majority of the infiltrating lymphocytes were CD3+, CD5+ and CD43+, more CD4+ than CD8+, and only a small minority was CD20+. The cells did not stain for bcl-1 protein and CD30, and with no evidence of clonality. The DIF test result was negative. The IBLR eruption associated with MCL resembles clinically and histologically IBLR associated with CLL. The eruption seems to be reactive rather than neoplastic, because there is no evidence of MCL involvement in the skin lesions.

We have reported that the differentiation-inducing factor (DIF) is present in conditioned medium of mouse osteoblast-like cell (MC3T3-E1) cultures. In the present study, the DIF from conditioned medium of MC3T3-E1 cells was partially purified and its biologic activity was examined. The DIF was purified by monitoring the induction of phagocytic activity of mouse myeloblastic leukemia cells (M1). The DIF induced differentiation of not only M1 cells but also mouse myelomonocytic cells (WEHI-3). Furthermore, the DIF increased the in vitro bone-resorbing activity and the osteoclast number in mouse calvaria. The increases were inhibited by the addition of either salmon calcitonin or indomethacin. When mouse bone marrow cells were cultured with the DIF for 8 days, formation of osteoclast-like multinucleated cells was stimulated dose dependently. The DIF from MC3T3-E1 cells appeared to be different from interleukin-1 (IL-1), tumor necrosis factor (TNF), and transforming growth factor beta (TGF-beta). These results suggest that the DIF partially purified from osteoblast-like cell cultures stimulates osteoclastic bone resorption by promoting differentiation and fusion of osteoclast progenitors to form multinucleated osteoclasts.

BACKGROUND

Linear IgA bullous dermatosis (LAD) of children is relatively frequent in Africa.

OBJECTIVE

We undertook this study to evaluate the frequency of this disease among autoimmune bullous diseases (AIBDs) in Tunisian children.

METHODS

We present a 32-year retrospective study (January 1976 to December 2007). Children with chronic acquired bullous diseases seen at the Charles Nicolle Hospital of Tunis and for who direct immunofluorescence (DIF) of the perilesional skin demonstrated linear IgA immunoglobulin deposits were included in the study population.

RESULTS

Thirty-one children with LAD were selected representing 65.9% of all AIBDs of children selected in the same period, with a mean age of 5.5 years and a sex ratio (M/F) of 2.4. Most of the children had generalized eruption (28/31), more profuse on the face, pelvic region, buttocks and limbs. Mucosal lesions happened in only four children (12.9%). The mean duration of the disease was 14 months. DIF demonstrated linear IgA deposits along the dermal-epidermal junction in all patients. IgG, IgM, and complement were also seen (20/31). Indirect immunofluorescence was negative in 67% of cases. Eight patients responded to dapsone; however, prednisone had to be added in seven children to control the disease and erythromycin in four others. A long-term remission period was achieved in 76.1% of patients.

CONCLUSIONS

This study confirms that LAD is the most common AIBD in children in Tunisia which frequently occurs in preschool-aged males. Independently of the used drug, a long-term remission is frequently observed.

Out of 64 patients diagnosed with urticarial vasculitis (UV), 49 (76.6%) presented with their first attack of UV. The others experienced recurrent attacks with a mean number of 3.3 past recurrences. Fifteen patients had angioedema (23.4%) and 16 (25%) suffered systemic involvement. The most common abnormal laboratory finding was an increased erythrocyte sedimentation rate. Six of 62 patients (9.7%) had decreased C3 levels. A cause could be identified in 19 patients (29.7%). The most common identified cause was infection; other causes included drugs, malignancy and systemic lupus erythematosus (SLE). The prevalence of immunoreactant deposits in the skin lesions measured by DIF was 54.7% (35 of 64 patients). The median disease duration of each episode was 85 days. The probability that patients were free of symptoms within one year was 70%. Patients with an idiopathic cause had a statistically significant longer course duration of each episode than the group with upper respiratory tract infection. Compared to reports from Westem countries, our patients seemed to have less severe symptoms and a lower percentage of hypocomplementemic UV and SLE.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD; dioxin), a member of a class of environmental pollutants represented by polychlorinated dibenzo-p-dioxins and dibenzofurans, is one of the most toxic artificial compounds ever developed. In this study, we identified a novel TCDD target gene, DIF-3 (dioxin inducible factor-3), by cDNA representational difference analysis. DIF-3 protein is a nuclear factor and possesses a zinc-finger motif at its N-terminus. High DIF-3 mRNA expression in the testes was demonstrated by Northern blot analysis and abundant DIF-3 protein was detected during spermatogenesis. Thus, these results suggest that DIF-3 may be a target gene mediating the reproductive toxicity induced by TCDD.

BACKGROUND

Research and practice in autism spectrum disorder (ASD) rely on quantitative measures, such as the Social Responsiveness Scale (SRS), for characterization and diagnosis. Like many ASD diagnostic measures, SRS scores are influenced by factors unrelated to ASD core features. This study further interrogates the psychometric properties of the SRS using item response theory (IRT), and demonstrates a strategy to create a psychometrically sound short form by applying IRT results.

METHODS

Social Responsiveness Scale analyses were conducted on a large sample (N = 21,426) of youth from four ASD databases. Items were subjected to item factor analyses and evaluation of item bias by gender, age, expressive language level, behavior problems, and nonverbal IQ.

RESULTS

Item selection based on item psychometric properties, DIF analyses, and substantive validity produced a reduced item SRS short form that was unidimensional in structure, highly reliable (α = .96), and free of gender, age, expressive language, behavior problems, and nonverbal IQ influence. The short form also showed strong relationships with established measures of autism symptom severity (ADOS, ADI-R, Vineland). Degree of association between all measures varied as a function of expressive language.

CONCLUSIONS

Results identified specific SRS items that are more vulnerable to non-ASD-related traits. The resultant 16-item SRS short form may possess superior psychometric properties compared to the original scale and emerge as a more precise measure of ASD core symptom severity, facilitating research and practice. Future research using IRT is needed to further refine existing measures of autism symptomatology.

BACKGROUND

The Patient Health Questionnaire (PHQ-9) and Hospital Anxiety and Depression Scale (HADS) are commonly used measures in clinical practice and research. It is important that such scales measure the trait they purport to measure and that the impact of other measurement artefacts is minimal. Differential item functioning of these scales by gender, educational background and age is currently assessed.

METHODS

Severity of depression and anxiety symptoms were measured in primary care patients referred to mental health workers using the PHQ-9 and HADS. Each scale was assessed for Differential Item Functioning (DIF) and Differential Test Function (DTF) by gender, educational background and age. Minimum n per analysis=895. DIF was assessed with Mantel's χ(2), Liu-Agresti cumulative common odds ratio (LA LOR) and the standardised LA LOR (LA LOR-Z). DTF was assessed in relation to ν(2).

RESULTS

PHQ-9, HADS Depression Sub-scale (HADS-D) and HADS Anxiety Subscale (HADS-A) lacked bias in terms of gender and educational background (ν(2)<0.07). However, both PHQ-9 and HADS-D exhibited bias with regard to age: PHQ-9 ν(2)=0.103 (medium effect); HADS-D ν(2)=0.214 (large effect). PHQ-9 items exhibiting DIF by age covered: anhedonia, energy and low mood. HADS-D items exhibiting DIF by age covered psychomotor retardation and interest in appearance.

CONCLUSIONS

No assessment of other potential DIF contributors was made.

CONCLUSIONS

PHQ-9, HADS-D and HADS-A generally do not exhibit bias for gender and educational background. However bias was observed in PHQ-9 and HADS-D for age. Caution should be exercised interpreting scores both in clinical practice and research.

The Dictyostelium transcription factor STATc is tyrosine phosphorylated and accumulates in the nucleus when cells are exposed either to hyper-osmotic stress or to the prestalk-inducing polyketide DIF-1. In the case of stress STAT activation is mediated by regulated dephosphorylation; whereby two serine residues on PTP3, the tyrosine phosphatase that de-activates STATc, become phosphorylated after exposure to stress so inhibiting enzymatic activity. We now show that the more highly regulated of the two PTP3 serine residues, S747, is also phosphorylated in response to DIF-1, suggesting a common activation mechanism. Hyper-osmotic stress causes a re-distribution of F-actin to the cortex, cell rounding and shrinkage and we show that DIF-1 induces a similar but transient F-actin re-distribution and rounding response. We also find that two mechanistically distinct inhibitors of actin polymerization, latrunculin A and cytochalasin A induce phosphorylation at S747 of PTP3 and activate STATc. We suggest that PTP3 phosphorylation, and consequent STATc activation, are regulated by changes in F-actin polymerization status during stress and DIF-induced cytoskeletal remodelling.

DPYK3, a member of the Dictyostelium TKL (tyrosine kinase like) kinase family, was ablated by homologous recombination. dpyk3- cells displayed aberrant pattern formation during development. The prestalk O zone was not properly formed and, instead, the prespore zone was expanded in dpyk3- slugs. During development, the transcription factor STATc (signal transducers and activators of transcription c) was persistently phosphorylated and ecmAO expression level was kept low in dpyk3- cells. Furthermore, in response to differentiation inducing factor-1 (DIF-1) in suspension culture, dpyk3- cells displayed persistent STATc phosphorylation and reintroduction of DPYK3 in dpyk3- cells restored transient STATc phosphorylation similarly to wild type cells. In contrast to the positive STAT regulation by Janus Kinase in metazoans, Dictyostelium DPYK3 negatively regulates STATc during development in response to DIF-1 signaling.

We show that antiphase light-temperature cycles (negative day-night temperature difference [-DIF]) inhibit hypocotyl growth in Arabidopsis (Arabidopsis thaliana). This is caused by reduced cell elongation during the cold photoperiod. Cell elongation in the basal part of the hypocotyl under -DIF was restored by both 1-aminocyclopropane-1-carboxylic acid (ACC; ethylene precursor) and auxin, indicating limited auxin and ethylene signaling under -DIF. Both auxin biosynthesis and auxin signaling were reduced during -DIF. In addition, expression of several ACC Synthase was reduced under -DIF but could be restored by auxin application. In contrast, the reduced hypocotyl elongation of ethylene biosynthesis and signaling mutants could not be complemented by auxin, indicating that auxin functions upstream of ethylene. The PHYTOCHROME INTERACTING FACTORS (PIFs) PIF3, PIF4, and PIF5 were previously shown to be important regulators of hypocotyl elongation. We now show that, in contrast to pif4 and pif5 mutants, the reduced hypocotyl length in pif3 cannot be rescued by either ACC or auxin. In line with this, treatment with ethylene or auxin inhibitors reduced hypocotyl elongation in PIF4 overexpressor (PIF4ox) and PIF5ox but not PIF3ox plants. PIF3 promoter activity was strongly reduced under -DIF but could be restored by auxin application in an ACC Synthase-dependent manner. Combined, these results show that PIF3 regulates hypocotyl length downstream, whereas PIF4 and PIF5 regulate hypocotyl length upstream of an auxin and ethylene cascade. We show that, under -DIF, lower auxin biosynthesis activity limits the signaling in this pathway, resulting in low activity of PIF3 and short hypocotyls.

Tyrosine recombinases are conserved in the three kingdoms of life. Here we present the first crystal structure of a full-length archaeal tyrosine recombinase, XerA from Pyrococcus abyssi, at 3.0 Å resolution. In the absence of DNA substrate XerA crystallizes as a dimer where each monomer displays a tertiary structure similar to that of DNA-bound Tyr-recombinases. Active sites are assembled in the absence of dif except for the catalytic Tyr, which is extruded and located equidistant from each active site within the dimer. Using XerA active site mutants we demonstrate that XerA follows the classical cis-cleavage reaction, suggesting rearrangements of the C-terminal domain upon DNA binding. Surprisingly, XerA C-terminal αN helices dock in cis in a groove that, in bacterial tyrosine recombinases, accommodates in trans αN helices of neighbour monomers in the Holliday junction intermediates. Deletion of the XerA C-terminal αN helix does not impair cleavage of suicide substrates but prevents recombination catalysis. We propose that the enzymatic cycle of XerA involves the switch of the αN helix from cis to trans packing, leading to (i) repositioning of the catalytic Tyr in the active site in cis and (ii) dimer stabilisation via αN contacts in trans between monomers.

The technique of diffusive gradients in thin-films (DGT) accumulates metals on a Chelex resin after their diffusive transport through a hydrogel. It lowers metal concentrations in soil solution adjacent to the device and induces resupply of metal associated with the solid phase. DGT devices were deployed in an alluvial gley soil for 21 different time periods between 4 h and 19.5 d. The accumulated masses of Cu, Cd, Ni, and Zn were used to calculate the distribution coefficient for labile metal, Kdl, and adsorption and desorption rate constants. Calculations were performed using a dynamic numerical model of DGT-induced fluxes in soils (DIFS). It assumes first-order exchange between solid phase and solution and diffusional transport in both the soil solution and the hydrogel. The DIFS model fitted changes in accumulated mass with time very well. Values of Kdl calculated from DIFS of 100 (Cd), 250 (Cu), 150 (Ni), and 150 (Zn) were larger than values of distribution coefficients estimated by exchange with Ca(NO3)2 but similar to those estimated by isotopic exchange (Cd and Zn only). These results suggest that the solid-phase pool of metal affected by the removal of labile metal by DGT, which operates on a time scale of minutes, is similar to the solid-phase pool of metal that can isotopically exchange with solution on a time scale of 2 d. Response times of minutes were consistent with interaction rates with surfaces, and desorption rate constants agreed with other reported values. An appraisal of the DIFS model demonstrated the importance of the labile pool size in the solid phase for controlling supply to a sink, such as DGT or a plant. As values of Kdl and kinetic parameters are obtained using DGT with minimal soil disturbance and by a similar mechanism to that involved in plant uptake, they may be pertinent to bioavailability studies.

OBJECTIVE

In child-parent agreement studies in the field of paediatric health-related quality of life (HRQoL), little attention has been paid to the effect of gender in parental proxy rating of children's HRQoL. This study aims to test the potential interchangeability of parent dyads in reporting children's HRQoL on both item and scale levels of the PedsQL™ 4.0 instrument, using the approach of differential item functioning (DIF).

METHODS

The PedsQL™ 4.0 Generic Core Scales were completed by 576 father-and-mother dyads. A polytomous item response theory model, graded response model, was used to detect DIF across fathers and mothers.

RESULTS

Assessment at item level showed that fathers and mothers perceived the meaning of items of the PedsQL™ 4.0 consistently. Regarding the scale level, a moderate to high level of agreement was observed between mothers' and fathers' reports on all similar subscales. Although the significant mean score differences in total, physical and emotional functioning indicated that fathers gave higher scores to their children, the small effect size implied that this difference may not be practically meaningful.

CONCLUSIONS

Our findings revealed that discrepancy in parent dyads in rating children's HRQoL is a "real" difference and not an artefact due to measurement non-invariance. Fathers were seen to have slightly different insights into their children, especially for emotional functioning, but overall the results were not all that different. This suggests that paternal proxy-reports can be included in studies along with maternal proxy-reports, and the two may be combined when looking at parent-child agreement. Parent-child agreement studies in Iran are not affected by parents' gender, and therefore, researchers may rely on the assumption of the interchangeability of fathers and mothers in these studies.

The aim of this study was to evaluate the incidence and morbidities of Chlamydia trachomatis infections in newborn infants. Tissue culture and direct immunofluorescence (DIF) tests were used to detect the presence of nasopharyngeal C. trachomatis infection in 35 preterm and 21 healthy term neonates. All infants were followed up clinically for 3 months, and enzyme-linked immunosorbent assay analysis for serum antichlamydial IgG and IgM was performed on day 15 and week 6. Tissue culture and/or DIF studies showed that 10 of the preterm infants (28.57%), but none of the term infants, were C. trachomatis-positive. The sensitivities of DIF and tissue culture were 40% and 70%, respectively, demonstrating the diagnostic superiority of tissue culture tests for detecting C. trachomatis. Only one asymptomatic preterm infant was found to be positive for antichlamydial antibodies at the 6th week. All C. trachomatis-positive infants were given macrolide antibiotics for 14 days. The study showed that male infants were more frequently infected, but types of delivery, mean gestational ages, mean birth weights, and the need for mechanical ventilation were similar in C. trachomatis-infected and uninfected preterm infants. However, the duration of oxygen treatment was longer in infected preterm infants. Clinical conjunctivitis was more frequent in C. trachomatis-infected infants (60%) than in uninfected infants (24%). C. trachomatis-positive infants had pneumonia more frequently; however, all patients with pneumonia were negative for antichlamydial IgM and IgG antibodies. Macrolide treatment for 2 weeks for nasopharyngeal C. trachomatis positivity may have prevented C. trachomatis related pneumonia, but it may not have significantly influenced the risk of pneumonia caused by other agents. Chlamydial infections may lead to early and late respiratory problems in preterm infants. Nasopharyngeal screening may help physicians detect C. trachomatis infections and provide a means of early diagnosis in this vulnerable patient group.

Stalk cell differentiation during development of the slime mould Dictyostelium is induced by a chlorinated alkyl phenone called differentiation-inducing factor-1 (DIF-1). Inactivation of DIF-1 is likely to be a key element in the DIF-1 signalling system, and we have shown previously that this is accomplished by a dedicated metabolic pathway involving up to 12 unidentified metabolites. We report here the structure of the first four metabolites produced from DIF-1, as deduced by m.s., n.m.r. and chemical synthesis. The structures of these compounds show that the first step in metabolism is a dechlorination of the phenolic ring, producing DIF metabolite 1 (DM1). DM1 is identical with the previously known minor DIF activity, DIF-3. DIF-3 is then metabolized by three successive oxidations of its aliphatic side chain: a hydroxylation at omega-2 to produce DM2, oxidation of the hydroxy group to a ketone group to produce DM3 and a further hydroxylation at omega-1 to produce DM4, a hydroxyketone of DIF-3. We have investigated the enzymology of DIF-1 metabolism. It is already known that the first step, to produce DIF-3, is catalysed by a novel dechlorinase. The enzyme activity responsible for the first side-chain oxidation (DIF-3 hydroxylase) was detected by incubating [3H]DIF-3 with cell-free extracts and resolving the reaction products by t.l.c. DIF-3 hydroxylase has many of the properties of a cytochrome P-450. It is membrane-bound and uses NADPH as co-substrate. It is also inhibited by CO, the classic cytochrome P-450 inhibitor, and by several other cytochrome P-450 inhibitors, as well as by diphenyliodonium chloride, an inhibitor of cytochrome P-450 reductase. DIF-3 hydroxylase is highly specific for DIF-3: other closely related compounds do not compete for the activity at 100-fold molar excess, with the exception of the DIF-3 analogue lacking the chlorine atom. The Km for DIF-3 of 47 nM is consistent with this enzyme being responsible for DIF-3 metabolism in vivo. The two further oxidations necessary to produce DM4 are also performed in vitro by similar enzyme activities. One of the inhibitors of DIF-3 hydroxylase, ancymidol (IC50 67 nM) is likely to be particularly suitable for probing the function of DIF metabolism during development.

BACKGROUND

Cutaneous vasculitis presents as a mosaic of clinical and histological findings. Its pathogenic mechanisms and clinical manifestations are varied.

OBJECTIVE

To study the epidemiological spectrum of cutaneous vasculitides as seen in a dermatologic clinic and to determine the clinico-pathological correlation.

METHODS

A cohort study was conducted on 50 consecutive patients clinically diagnosed as cutaneous vasculitis in the dermatology outdoor; irrespective of age, sex and duration of the disease. Based on the clinical presentation, vasculitis was classified according to modified Gilliam's classification. All patients were subjected to a baseline workup consisting of complete hemogram, serum-creatinine levels, serum-urea, liver function tests, chest X-ray, urine (routine and microscopic) examination besides antistreptolysin O titer, Mantoux test, cryoglobulin levels, antineutrophilic cytoplasmic antibodies and hepatitis B and C. Histopathological examination was done in all patients while immunofluorescence was done in 23 patients.

RESULTS

Out of a total of 50 patients diagnosed clinically as cutaneous vasculitis, 41 were classified as leukocytoclastic vasculitis, 2 as Heinoch-Schonlein purpura, 2 as urticarial vasculitis and one each as nodular vasculitis, polyarteritis nodosa and pityriasis lichenoid et varioliforme acuta. Approximately 50% of the patients had a significant drug history, 10% were attributed to infection and 10% had positive collagen workup without any overt manifestations, while 2% each had Wegener granulomatosis and cryoglobulinemia. No cause was found in 26% cases. Histopathology showed features of vasculitis in 42 patients. Only 23 patients could undergo direct immunofluorescence (DIF), out of which 17 (73.9%) were positive for vasculitis.

CONCLUSIONS

Leukocytoclastic vasculitis was the commonest type of vaculitis presenting to the dermatology outpatient department. The workup of patients with cutaneous vasculitis includes detailed history, clinical examination and investigations to rule out multisystem involvement followed by skin biopsy and DIF at appropriate stage of evolution of lesions. Follow up of these patients is very essential as cutaneous manifestations may be the forme fruste of serious systemic involvement.

BACKGROUND

Translations of questionnaires need to be carefully validated to assure that the translation measures the same construct(s) as the original questionnaire. The four-dimensional symptom questionnaire (4DSQ) is a Dutch self-report questionnaire measuring distress, depression, anxiety and somatization.

OBJECTIVE

To evaluate the equivalence of the English version of the 4DSQ.

METHODS

4DSQ data of English and Dutch speaking general practice attendees were analysed and compared. The English speaking group consisted of 205 attendees, aged 18-64 years, in general practice, in Canada whereas the Dutch group consisted of 302 general practice attendees in the Netherlands. Differential item functioning (DIF) analysis was conducted using the Mantel-Haenszel method and ordinal logistic regression. Differential test functioning (DTF; i.e., the scale impact of DIF) was evaluated using linear regression analysis.

RESULTS

DIF was detected in 2/16 distress items, 2/6 depression items, 2/12 anxiety items, and 1/16 somatization items. With respect to mean scale scores, the impact of DIF on the scale level was negligible for all scales. On the anxiety scale DIF caused the English speaking patients with moderate to severe anxiety to score about one point lower than Dutch patients with the same anxiety level.

CONCLUSIONS

The English 4DSQ measures the same constructs like the original Dutch 4DSQ. The distress, depression and somatization scales can employ the same cut-off points as the corresponding Dutch scales. However, cut-off points of the English 4DSQ anxiety scale should be lowered by one point to retain the same meaning as the Dutch anxiety cut-off points.

Differentiation-inducing factor-1 (DIF-1), a morphogen for Dictyostelium discoideum, inhibits the proliferation of human cancer cell lines by suppressing the Wnt/β-catenin signaling pathway. In this study, we examined the effect of DIF-1 on c-Myc, a target gene product of the Wnt/β-catenin signaling pathway, mainly using HCT-116 colon cancer cells. DIF-1 strongly reduced the amount of c-Myc protein in time- and concentration-dependent manners and reduced c-Myc mRNA expression by inhibiting promoter activity through the TCF binding sites. The effect of DIF-1 on c-Myc was also confirmed using the human cervical cell line HeLa. Pretreatment with the proteasome inhibitor MG132 or glycogen synthase kinase-3β (GSK-3β) inhibitors (LiCl and SB216763) attenuated the effect of DIF-1, suggesting that DIF-1 induced c-Myc protein degradation through GSK-3β activation. Furthermore, we examined whether c-Myc was involved in the anti-proliferative effect of DIF-1 using c-Myc-overexpressing cells and found that c-Myc was associated with the anti-proliferative effect of this compound. These results suggest that DIF-1 inhibits c-Myc expression by inhibiting promoter activity and inducing protein degradation via GSK-3β activation, resulting in the inhibition of cell proliferation. Since c-Myc seems to be profoundly involved in accelerated proliferation of various malignant tumors, DIF-1 may have a potential to develop into a novel anti-cancer agent.

OBJECTIVE

The aim of this study was to assess the contribution of left ventricular (LV) systolic dyssynchrony to functional mitral regurgitation (MR).

RESULTS

Patients (n = 136) with LV systolic dysfunction (ejection fraction <50%) and at least mild MR were prospectively recruited. The effective regurgitant orifice area (EROA) was assessed by the proximal isovelocity surface area method. Left ventricular global systolic dyssynchrony [the maximal difference in time to peak systolic velocity among the 12 LV segments (Ts-Dif)] and regional systolic dyssynchrony (the delay between the anterolateral and posteromedial papillary muscle attaching sites) were assessed by tissue Doppler imaging. Left ventricular global and regional remodelling, systolic function, indices of mitral valvular and annular deformation were also measured. The size of the EROA correlated with the degrees of mitral deformation, LV remodelling, systolic function, and systolic dyssynchrony. By multivariate logistic regression analysis, the mitral valve tenting area (OR = 1.020, P < 0.001) and the Ts-Dif (OR = 1.011, P = 0.034) were independent determinants of significant functional MR (defined by EROA ≥20 mm(2)). From the receiver-operating characteristic curve, the tenting area of 2.7 cm(2) (sensitivity 83%, specificity 82%, AUC 0.86, P < 0.001) and the Ts-Dif of 85 ms (sensitivity 66%, specificity 72%, AUC 0.74, P < 0.001) were associated with significant functional MR. The assessment of Ts-Dif showed an incremental value over the mitral valve tenting area for determining functional MR (χ(2) = 53.92 vs.49.11, P = 0.028).

CONCLUSIONS

This cross-sectional study showed that LV global, but not regional systolic dyssynchrony, is a determinant of significant functional MR in patients with LV systolic dysfunction, and is incremental to the tenting area that is otherwise the strongest factor for mitral valve deformation.

To systematically evaluate the whole-transcriptome sequencing data of cholangiocarcinoma (CHOL) to gain more insights into the transcriptomic landscape and molecular mechanism of this cancer, we performed whole-transcriptome sequencing based on the tumorous (C) and their corresponding non-tumorous adjacent to the tumors (CP) from eight CHOL patients. Subsequently, differential expression analysis was performed on the C and CP groups, followed by functional interaction prediction analysis to investigate gene-regulatory circuits in CHOL. In addition, The Cancer Genome Atlas (TCGA) for CHOL data was used to validate the results. In total, 2,895 differentially expressed messenger RNAs (dif-mRNAs), 56 differentially expressed microRNAs (dif-miRNAs), 151 differentially expressed long non-coding RNAs (dif-lncRNAs), and 110 differentially expressed circular RNAs (dif-circRNAs) were found in CHOL samples compared with controls. Enrichment analysis on those differentially expressed genes (DEGs) related to miRNA, lncRNA, and circRNA also identified the function of spliceosome. The downregulated hsa-miR-144-3p were significantly enriched in the competing endogenous RNA (ceRNA) complex network, which also included 7 upregulated and 13 downregulated circRNAs, 7 upregulated lncRNAs, and 90 upregulated and 40 downregulated mRNAs. Moreover, most of the DEGs and a few of the miRNAs (such as hsa-miR-144-3p) were successfully validated by TCGA data. The genes involved in RNA splicing and protein degradation processes and miR-144-3p may play fundamental roles in the pathogenesis of CHOL.

Keywords: CHOL; DEG; ceRNA; miR-144-3p; spliceosome.

OBJECTIVE

To perform a cross-cultural adaptation of the Portuguese version of the Maslach Burnout Inventory for students (MBI-SS), and investigate its reliability, validity and cross-cultural invariance.

METHODS

The face validity involved the participation of a multidisciplinary team. Content validity was performed. The Portuguese version was completed in 2009, on the internet, by 958 Brazilian and 556 Portuguese university students from the urban area. Confirmatory factor analysis was carried out using as fit indices: the χ²/df, the Comparative Fit Index (CFI), the Goodness of Fit Index (GFI) and the Root Mean Square Error of Approximation (RMSEA). To verify the stability of the factor solution according to the original English version, cross-validation was performed in 2/3 of the total sample and replicated in the remaining 1/3. Convergent validity was estimated by the average variance extracted and composite reliability. The discriminant validity was assessed, and the internal consistency was estimated by the Cronbach's alpha coefficient. Concurrent validity was estimated by the correlational analysis of the mean scores of the Portuguese version and the Copenhagen Burnout Inventory, and the divergent validity was compared to the Beck Depression Inventory. The invariance of the model between the Brazilian and the Portuguese samples was assessed.

RESULTS

The three-factor model of Exhaustion, Disengagement and Efficacy showed good fit (c 2/df = 8.498, CFI = 0.916, GFI = 0.902, RMSEA = 0.086). The factor structure was stable (λ:χ²dif = 11.383, p = 0.50; Cov: χ²dif = 6.479, p = 0.372; Residues: χ²dif = 21.514, p = 0.121). Adequate convergent validity (VEM = 0.45;0.64, CC = 0.82;0.88), discriminant (ρ² = 0.06;0.33) and internal consistency (α = 0.83;0.88) were observed. The concurrent validity of the Portuguese version with the Copenhagen Inventory was adequate (r = 0.21, 0.74). The assessment of the divergent validity was impaired by the approach of the theoretical concept of the dimensions Exhaustion and Disengagement of the Portuguese version with the Beck Depression Inventory. Invariance of the instrument between the Brazilian and Portuguese samples was not observed (λ:χ²dif = 84.768, p<0.001; Cov: χ²dif = 129.206, p < 0.001; Residues: χ²dif = 518.760, p < 0.001).

CONCLUSIONS

The Portuguese version of the Maslach Burnout Inventory for students showed adequate reliability and validity, but its factor structure was not invariant between the countries, indicating the absence of cross-cultural stability.